Fig. 2: Large-scale fabrication of Janus particle-engineered structural lipiodol droplets.

a Photograph of the obtained Janus particle-engineered structural lipiodol droplets. Scale bars: 3 mm. b Optical microscope images of the obtained Janus particle-engineered structural lipiodol droplets. Scale bars: 100 μm. c Size distribution of Janus particle-engineered structural lipiodol droplets. The obtained Janus particle-engineered structural lipiodol droplets exhibited spherical shapes with sizes of 120 ± 40 μm. d–f Optical microscope images of the distribution of Janus particles on the interface of a lipiodol droplet. Scale bars: 20 μm. g Computed tomography (CT) image of the obtained Janus particle-engineered structural lipiodol droplet. Scale bars: 40 μm. h Confocal microscopy images of a single Janus particle-engineered structural lipiodol droplet. The Janus particles and lipiodol were labeled with amino fluorescein dye and Nile red, respectively. The results clearly demonstrated that these Janus particles were densely distributed onto the interface of a lipiodol droplet; the overlap between the Janus particles (green fluorescence) and lipiodol (red fluorescence) appeared yellow. Scale bars: 40 μm. i, j Size control of Janus particle-engineered structural lipiodol droplets. The sizes of Janus particle-engineered structural lipiodol droplets could be controlled from 25 ± 16 to 480 ± 53 μm by tuning the concentration of Janus particles and rates of lipiodol and deionized water (n = 3 independent samples). Data are presented as means ± SD. Experiments were performed three times (a, b, d–f, h), with similar results.